Battle of Mengyin

The Battle of Mengyin occurred in 293 AD during the War of the Eight Princes when Prince Sima Yue and his army marched north to invade the lands of the rival prince Sima Yao in Dong Commandery. Sima Yao and his general Hu Shuning were slain in the battle, and the mining town fell soon after, destroying Sima Yao's faction.

Background
In 292 AD, the Prince of Donghai Sima Yue conquered the land of the rebellious Prince of Pengcheng, Sima Zhi, adding Pengcheng to his territory. His northerly neighbor, Prince Sima Yao of Dongan, felt threatened by his expansion and preemptively declared war on him. This was an unwise move, as Sima Yue had a much larger army than Sima Yao. Sima Yue marched north with his army, and, as he marched, the major prince Sima Wei of Chen Commandery declared war on him. However, Sima Wei was preoccupied with taking control of Luoyang, so Sima Yue decided to eliminate Sima Yao first. Sima Yue and his army of 1,093 troops besieged the Dong iron mines, which served as the capital of Sima Yao's domain; he faced 1,285 troops, so, rather than assault the town, he decided to lure out the attackers.

Battle
Sure enough, Sima Yao and his general Hu Shuning decided to sortie out of the city with their larger army, predicting that they would easily defeat Sima Yue's army. The two armies met in the woods, where their forces were obscured until Sima Yue rode into a clearing to lure out his rivals. Sima Yue then rode back into the woods, with Sima Yao's troops pursuing him. An entire unit was massacred by a massive colley of arrows, and the two armies met in melee as the cavalry battled on both flanks. Sima Yue, He Lun, and Princess Pei sought out the enemy generals, and Princess Pei slew Hu Shuning, while Sima Yue tracked down and slew Sima Yao. Sima Yue then rallied his forces and destroyed the defending army, and Ying Wan inherited Sima Yao's lands. Shortly after, Sima Yue launched a follow-up assault on the town, destroying Sima Yao and Ying Wan's faction.